Big Ten Academic Alliance Geospatial Discovery Portal

Big Ten Academic Alliance Geoportal

Mosaic of Illinois 7.5-minute Digital Raster Graphic (DRG) Images, 2003

Author:
Description:
This is a statewide ArcSDE Raster Mosaic of USGS DRG images of 7.5-minute topographic quadrangles occurring in Illinois. These are unmodified DRG images as distributed by the USGS, except (1) collar information has been removed for map tiling and (2) the data have been reprojected to the customary ISGS Lambert Conformal Conic projection (NAD 27). The map scale is 1:24,000. The map units are meters. The images were scanned at 250 dpi, giving an approximate raster cell resolution of 2.5 meters.
Collection:
Illinois Geospatial Data Clearinghouse
Place:
Illinois, United States
Subject:
Imagery and Base Maps
Year:
2003
Contributed by:
Illinois
More details at
Attribute Value
Click on map to inspect values